Loaded with Christian mythology and imagery and perfectly eloquent in verse, this selection of Blake's does a great job of collecting his best hits along with fleshed-out contextual background.
If you're writing a paper on Blake, this is the perfect book. If you just want to sit back and read Blake's works, I don't recommend it. The majority of the book is the editor's descriptions, interpretations, and opinions. Most of the poems and prose included are only fragments.